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IAB Tech Lab Launches New Supply Chain Validation Service for Publishers

NEW YORK, NY – June 29, 2021 – IAB Tech Lab announced today that it released a new automated service for publishers’ Supply Chain Validation. This service allows publishers to validate authorized sellers of their inventory by verifying their ads.txt (authorized digital sellers file) or app-ads.txt files against sellers.json files programmatically. 

Two of the most widely adopted sell-side transparency specifications from IAB Tech Lab, ads.txt and app-ads.txt help eliminate misrepresented, fraudulent inventory by providing a mechanism for publishers to publicly list who is authorized to sell their inventory. The accompanying sellers.json specification enables buyers to verify the entities who are either direct sellers of, or intermediaries in the selected digital advertising opportunity for purchase. The Supply Chain Validation service: 

  1. Validates information between both ads.txt and sellers.json daily
  2. Notifies the publisher of inconsistencies between their listed sellers and the referenced sellers.json files
  3. Makes validation results accessible to all IAB Tech Lab members 

“IAB Tech Lab seeks to make our specifications as easy to implement and use as possible,” said Shailley Singh, acting General Manager and SVP, Product Management, IAB Tech Lab. “For a specification used so widely and relied on daily for the integrity of programmatic transactions, it’s critical that publishers have an automated way to verify how their authorized selling partners represent them. Ultimately, Supply Chain Validation aims to ensure that sell-side transparency standards are properly implemented and give buyers and publishers more confidence to transact.” 

Supply Chain Validation is available for registration now in the IAB Tech Lab Tools portal at Publishers of websites and mobile apps can subscribe to the service for an annual fee. 

Check here for the detailed automated test cases the validation executes and reports.

With IAB Tech Lab’s release of the new Supply Chain Validation service, we wanted to look at the state of these standards in-market and share our findings and recommendations with the industry in a webinar: The State of Ads.txt Adoption: Validating the Supply Chain. IAB Tech Lab analyzed over 3 million websites using ads.txt, 400,000 apps using app-ads.txt, and hundreds of sellers.json files. We will share our findings for common syntactical errors, relationship validations between ads.txt/sellers.json, and more to help with your implementation and monitoring of your supply chain with these tools.

Register now for one of the two following sessions (based on your time zone) and join us for further insights and discussion with our Tech Lab experts:

About IAB Technology Laboratory

Established in 2014, the IAB Technology Laboratory (Tech Lab) is a non-profit consortium that engages a member community globally to develop foundational technology and standards that enable growth and trust in the digital media ecosystem. Comprised of digital publishers, ad technology firms, agencies, marketers, and other member companies, IAB Tech Lab focuses on solutions for brand safety and ad fraud; identity, data, and consumer privacy; ad experiences and measurement; and programmatic effectiveness. Its work includes the OpenRTB real-time bidding protocol, ads.txt anti-fraud specification, Open Measurement SDK for viewability and verification, VAST video specification, and Project Rearc initiative for privacy-centric addressability. Board members/companies are listed at For more information, please visit

IAB Tech Lab Media Contacts

Kate Tumino / Brittany Tibaldi
212-896-1252 / 347-487-6794  /